Improper Certificate Validation
When libvirtd is configured by OSP director (tripleo-heat-templates) to use the TLS transport it defaults to the same certificate authority as all non-libvirtd services. As no additional authentication is configured this allows these services to connect to libvirtd (which is equivalent to root access). If a vulnerability exists in another service it could, combined with this flaw, be exploited to escalate privileges to gain control over compute nodes.
CWE-295 - Improper Certificate Validation
The authenticity component of a web system stems from the ability to validate “Digital certificates”, which (i) establish trust between two or more entities sharing data over a network; (ii) ensure data at rest and transit is secure from unauthorized access; and (iii) check the identity of the actors that interact with the system. An application with absent or ineffective certificate validation mechanisms allows malicious users, impersonating trusted hosts, to manipulate the communication path between the client and the host, resulting in unauthorized access to data and to the application’s internal environment, and potentially enabling man-in-the-middle attacks.